CHA Zeolite Catalyst Regeneration via Hydrogen Gas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In industrial-scale propylene production from ethylene using a zeolite catalyst, the catalyst's ethylene conversion and propylene selectivity are compromised due to coke deposition, and conventional oxygen-containing gas regeneration methods fail to maintain high propylene selectivity while restoring ethylene conversion.
Innovation Solution
Regenerating the catalyst by contacting it with a hydrogen gas at a partial pressure of 0.01 MPa or more, without oxygen, at temperatures between 300°C and 750°C, to maintain high propylene selectivity and ethylene conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catalyst is regenerated by contacting with oxygen-containing gas to remove coke, then ethylene conversion is restored, but propylene selectivity decreases
Solution Approach 1:
The patent changes the chemical composition parameter of the regeneration gas from oxygen-containing to hydrogen-containing, and controls the hydrogen partial pressure at 0.01 MPa or more. This parameter change transforms the regeneration mechanism from oxidative combustion to hydrogenative removal, allowing coke removal while preserving the catalyst's propylene selectivity characteristics
Solution Approach 2:
The patent uses hydrogen atmosphere as an inert-like environment for the purpose of avoiding oxidative damage to the catalyst. By creating a hydrogen-rich environment with controlled partial pressure, the method prevents the formation of unwanted byproducts while effectively removing coke, thus maintaining high propylene selectivity during regeneration
2Manufacturing precision
If the catalyst is used after prolonged reaction time, then propylene selectivity remains high, but ethylene conversion decreases due to coke deposition
Solution Approach 1:
The patent implements periodic regeneration cycles where the catalyst is intermittently contacted with hydrogen gas during the reaction process. This periodic treatment removes accumulated coke before it completely deactivates the catalyst, maintaining both high ethylene conversion and propylene selectivity over extended operation periods
Solution Approach 2:
The hydrogen gas used for regeneration can be generated from the reaction system itself or recycled from process streams. The method allows the system to self-maintain catalyst activity through in-situ regeneration, reducing the need for external regeneration facilities and continuous catalyst replacement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively recovers ethylene conversion and maintains high propylene selectivity, enabling stable and efficient propylene production by preventing coke deposition and promoting catalyst regeneration in hydrogen.
Implementation Method 1
regenerating a catalyst comprising a zeolite as an active ingredient and having an ethylene conversion lowered through a reaction of producing propylene by bringing into contact with ethylene in a vapor phase, by bringing the catalyst into contact with a gas which does not comprise oxygen and comprises hydrogen
Data Source
AI summary
A method for manufacturing a catalyst, which comprises regenerating a catalyst comprising a CHA zeolite as an active ingredient and having an ethylene conversion lowered through reaction of producing propylene by bringing into contact with ethylene in a vapor phase, by bringing the catalyst into contact with a gas which does not comprise oxygen and comprises hydrogen having a hydrogen partial pressure of 0.01 MPa or more as an absolute pressure thereof.